Use MOZILLA_1_8_BRANCH ifdefs to limit the versions of Thunderbird and Firefox that specific Lightning builds will install in. This avoids user inconvenience and invalid bug-filing due to ABI compatibility issues. (Bug 323776), thanks to Stefan Sitter <ssitter@googlemail.com> for the patch, r=dmose.

calendar/lightning/Makefile.in

@@ -68,6 +68,9 @@ endif
 
 DEFINES += -DTHEME=$(THEME)
 
+DEFINES += -DTHUNDERBIRD_VERSION=$(THUNDERBIRD_VERSION)
+DEFINES += -DFIREFOX_VERSION=$(FIREFOX_VERSION)
+
 PREF_JS_EXPORTS = $(srcdir)/content/lightning.js
 
 include $(topsrcdir)/config/rules.mk

calendar/lightning/install.rdf

@@ -1,5 +1,6 @@
 <?xml version="1.0"?>
 
+#filter substitution
 <RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
      xmlns:em="http://www.mozilla.org/2004/em-rdf#">
 
@@ -10,8 +11,13 @@
       <Description>
         <!-- thunderbird -->
         <em:id>{3550f703-e582-4d05-9a08-453d09bdfdc6}</em:id>
-        <em:minVersion>1.0+</em:minVersion>
-        <em:maxVersion>1.6a1</em:maxVersion>
+#ifdef MOZILLA_1_8_BRANCH
+        <em:minVersion>1.5</em:minVersion>
+        <em:maxVersion>1.5.0.*</em:maxVersion>
+#else
+        <em:minVersion>@THUNDERBIRD_VERSION@</em:minVersion>
+        <em:maxVersion>@THUNDERBIRD_VERSION@</em:maxVersion>
+#endif
       </Description>
     </em:targetApplication>
 
@@ -19,8 +25,13 @@
       <Description>
         <!-- firefox -->
         <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
-        <em:minVersion>1.0+</em:minVersion>
-        <em:maxVersion>1.6a1</em:maxVersion>
+#ifdef MOZILLA_1_8_BRANCH
+        <em:minVersion>1.5</em:minVersion>
+        <em:maxVersion>1.5.0.*</em:maxVersion>
+#else
+        <em:minVersion>@FIREFOX_VERSION@</em:minVersion>
+        <em:maxVersion>@FIREFOX_VERSION@</em:maxVersion>
+#endif
       </Description>
     </em:targetApplication>